A sudden explosion of sewage from a toilet is much more than a run of the mill clog. It could mean that you have a significant blockage in the branch line between the sewer main and your bathroom. Your best option is to call a professional to clear out the drain line. In most cases, they will use a cable outfitted with three-inch blades. If you do not have a large enough clean-out port to accommodate the cable, the plumber may have to remove your toilet in order to snake the line.
When cleaning up following a sewage backup, be sure to take appropriate precautions, including wearing a mask and gloves to avoid making yourself, your family, and even your pets sick. Salmonella, Helicobacter pylori, and E. coli are just a few of bacteria found in sewage that can cause everything from gastrointestinal upset to hepatitis.